The program objective is to study the interaction of nucleic acids (native and synthetic) with the gene product protein 32 of T4 bacteriophage by spectroscopic methods. These methods will give information on the secondary and tertiary structure of the nucleic acids in the complex and the structure of the active sites of the protein. The most important methods will be: a. circular dichroism (CD); b. flow oriented circular dichroism; c. fluorescence detected circular dichroism (FDCD). These methods will give information concerning the following properties: a. the interaction between the bases of the nucleic acids, between the nucleic acids and the gp32 protein, and the structure and orientation of the active sites of the gp32 protein in the protein-DNA complex. With the help of the above information plus other available information in the literature, it is hoped that models satisfying the above results can be made to give an insight in the mechanism of DNA-protein interactions, gene suppression, gene expression and replication.